FAIR VALUE MEASUREMENT - Financial Assets Measured at Fair Value on a Recurring Basis using Level 3 Inputs (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Non-Agency
Gains (losses) included in net income
Included in gain (loss) on settlement of investments, net	$ 0
Excess MSRs Investees
Purchases, sales and repayments
New Residential’s ownership	50.00%	50.00%
Recurring Basis | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning	$ 13,681,878
Transfers from Level 3	0
Transfers to Level 3	0
Gains (losses) included in net income
Included in other-than-temporary impairment (''OTTI'') on securities	(6,670)
Included in change in fair value of investments in excess mortgage servicing rights	(45,691)
Included in change in fair value of investments in excess mortgage servicing rights, equity method investees	523
Included in servicing revenue, net	74,666
Included in change in fair value of investments in mortgage servicing rights financing receivables(D)	271,076
Included in change in fair value of servicer advance investments	(79,476)
Included in gain (loss) on settlement of investments, net	113,002
Included in other income (loss), net	2,592
Gains (losses) included in other comprehensive income	49,164
Interest income	103,926
Purchases, sales and repayments
Purchases	1,723,898
Proceeds from sales	(1,026)
Proceeds from repayments	(1,040,880)
New Ocwen Agreements (Note 5)	(2,823,412)
Balance, ending	12,023,570
Recurring Basis | Level 3 | Servicer Advances
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning	4,027,379
Transfers from Level 3	0
Transfers to Level 3	0
Gains (losses) included in net income
Included in other-than-temporary impairment (''OTTI'') on securities	0
Included in change in fair value of investments in excess mortgage servicing rights	0
Included in change in fair value of investments in excess mortgage servicing rights, equity method investees	0
Included in servicing revenue, net	0
Included in change in fair value of investments in mortgage servicing rights financing receivables(D)	0
Included in change in fair value of servicer advance investments	(79,476)
Included in gain (loss) on settlement of investments, net	72,585
Included in other income (loss), net	0
Gains (losses) included in other comprehensive income	0
Interest income	18,889
Purchases, sales and repayments
Purchases	880,618
Proceeds from sales	0
Proceeds from repayments	(761,793)
New Ocwen Agreements (Note 5)	(3,202,838)
Balance, ending	955,364
Recurring Basis | Level 3 | MSRs
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning	1,735,504
Transfers from Level 3	0
Transfers to Level 3	0
Gains (losses) included in net income
Included in other-than-temporary impairment (''OTTI'') on securities	0
Included in change in fair value of investments in excess mortgage servicing rights	0
Included in change in fair value of investments in excess mortgage servicing rights, equity method investees	0
Included in servicing revenue, net	74,666
Included in change in fair value of investments in mortgage servicing rights financing receivables(D)	0
Included in change in fair value of servicer advance investments	0
Included in gain (loss) on settlement of investments, net	0
Included in other income (loss), net	0
Gains (losses) included in other comprehensive income	0
Interest income	0
Purchases, sales and repayments
Purchases	319,495
Proceeds from sales	0
Proceeds from repayments	0
New Ocwen Agreements (Note 5)	0
Balance, ending	2,129,665
Recurring Basis | Level 3 | Mortgage Servicing Rights Financing Receivable
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning	598,728
Transfers from Level 3	0
Transfers to Level 3	0
Gains (losses) included in net income
Included in other-than-temporary impairment (''OTTI'') on securities	0
Included in change in fair value of investments in excess mortgage servicing rights	0
Included in change in fair value of investments in excess mortgage servicing rights, equity method investees	0
Included in servicing revenue, net	0
Included in change in fair value of investments in mortgage servicing rights financing receivables(D)	271,076
Included in change in fair value of servicer advance investments	0
Included in gain (loss) on settlement of investments, net	0
Included in other income (loss), net	0
Gains (losses) included in other comprehensive income	0
Interest income	0
Purchases, sales and repayments
Purchases	0
Proceeds from sales	(1,026)
Proceeds from repayments	0
New Ocwen Agreements (Note 5)	1,017,993
Balance, ending	1,886,771
Recurring Basis | Level 3 | Non-Agency
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning	5,974,789
Transfers from Level 3	0
Transfers to Level 3	0
Gains (losses) included in net income
Included in other-than-temporary impairment (''OTTI'') on securities	(6,670)
Included in change in fair value of investments in excess mortgage servicing rights	0
Included in change in fair value of investments in excess mortgage servicing rights, equity method investees	0
Included in servicing revenue, net	0
Included in change in fair value of investments in mortgage servicing rights financing receivables(D)	0
Included in change in fair value of servicer advance investments	0
Included in gain (loss) on settlement of investments, net	0
Included in other income (loss), net	(313)
Gains (losses) included in other comprehensive income	49,164
Interest income	75,678
Purchases, sales and repayments
Purchases	523,785
Proceeds from sales	0
Proceeds from repayments	(245,225)
New Ocwen Agreements (Note 5)	0
Balance, ending	6,371,208
Recurring Basis | Level 3 | MSRs Agency
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning	324,636
Transfers from Level 3	0
Transfers to Level 3	0
Gains (losses) included in net income
Included in other-than-temporary impairment (''OTTI'') on securities	0
Included in change in fair value of investments in excess mortgage servicing rights	(3,169)
Included in change in fair value of investments in excess mortgage servicing rights, equity method investees	0
Included in servicing revenue, net	0
Included in change in fair value of investments in mortgage servicing rights financing receivables(D)	0
Included in change in fair value of servicer advance investments	0
Included in gain (loss) on settlement of investments, net	0
Included in other income (loss), net	2,879
Gains (losses) included in other comprehensive income	0
Interest income	4,240
Purchases, sales and repayments
Purchases	0
Proceeds from sales	0
Proceeds from repayments	(15,201)
New Ocwen Agreements (Note 5)	0
Balance, ending	313,385
Recurring Basis | Level 3 | MSRs Agency | Excess MSRs Investees
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning	171,765
Transfers from Level 3	0
Transfers to Level 3	0
Gains (losses) included in net income
Included in other-than-temporary impairment (''OTTI'') on securities	0
Included in change in fair value of investments in excess mortgage servicing rights	0
Included in change in fair value of investments in excess mortgage servicing rights, equity method investees	523
Included in servicing revenue, net	0
Included in change in fair value of investments in mortgage servicing rights financing receivables(D)	0
Included in change in fair value of servicer advance investments	0
Included in gain (loss) on settlement of investments, net	0
Included in other income (loss), net	0
Gains (losses) included in other comprehensive income	0
Interest income	0
Purchases, sales and repayments
Purchases	0
Proceeds from sales	0
Proceeds from repayments	(7,402)
New Ocwen Agreements (Note 5)	0
Balance, ending	164,886
Recurring Basis | Level 3 | MSRs Non-Agency
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning	849,077
Transfers from Level 3	0
Transfers to Level 3	0
Gains (losses) included in net income
Included in other-than-temporary impairment (''OTTI'') on securities	0
Included in change in fair value of investments in excess mortgage servicing rights	(42,522)
Included in change in fair value of investments in excess mortgage servicing rights, equity method investees
Included in servicing revenue, net	0
Included in change in fair value of investments in mortgage servicing rights financing receivables(D)	0
Included in change in fair value of servicer advance investments
Included in gain (loss) on settlement of investments, net	40,417
Included in other income (loss), net	26
Gains (losses) included in other comprehensive income	0
Interest income	5,119
Purchases, sales and repayments
Purchases	0
Proceeds from sales	0
Proceeds from repayments	(11,259)
New Ocwen Agreements (Note 5)	(638,567)
Balance, ending	$ 202,291